Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/48—Silver or gold
  • B01J23/50—Silver
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
  • B01J23/66—Silver or gold
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D301/00—Preparation of oxiranes
  • C07D301/02—Synthesis of the oxirane ring
  • C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
  • C07D301/04—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen
  • C07D301/08—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen in the gaseous phase
  • C07D301/10—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen in the gaseous phase with catalysts containing silver or gold
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

• This invention relates to a silver catalyst to be used for the production of ethylene oxide by the catalytic gas-phase oxidation of ethylene with molecular oxygen and to a method for the manufacture of the silver catalyst.
• the silver catalyst which is used in the commercial production of ethylene oxide by the catalytic gas-phase oxidation of ethylene with molecular oxygen is required, for satisfactory performance of the function thereof, to exhibit high selectivity and high activity and enjoy a long catalyst life as possible.
• a catalyst for the production of alkylene oxide which catalyst contains copper, gold, zinc, cadmium, mercury, niobium, tantalum, molybdenum, tungsten, vanadium, or desirably chromium, calcium, magnesium, strontium, and/or more desirably barium, and preferably further an alkali metal, in an amount preceding the amount naturally present as an impurity or cement in the carrier and sufficient to manifest the action of a promoter.
• a catalyst for the production of alkylene oxide which catalyst contains silver deposited on a porous heat-resistant carrier possessing a specific surface area in the range of 0.05 to l0 m2/g and further contains sodium and at least one other alkali metal selected from the group consisting of potassium, rubidium, and caesium in a promoting amount in excess of the amount naturally present as an impurity or a binding agent in the carrier.
• a catalyst for the production of an alkylene oxide is obtained by depositing silver and optionally sodium or lithium in the form of corresponding salts on a carrier, heating the carrier and in the subsequent treatment, depositing thereon the salts of such alkali metals as potassium, rubidium, and caesium in conjunction with an amine and/or ammonia.
• a silver catalyst which, as a catalyst for the reaction of oxidation, has silver and, when necessary, further an alkali metal component or an alkaline earth metal component deposited on a non-acidic carrier containing alumina, silica, and titania in a total amount of not less than 99% by weight, containing metal of the Groups Va, VIa, VIIa, VIII, Ib, and IIb of the Periodic Table of Elements in a total amount of less than 0.l% by weight, and assuming no acid colour on exposure to methyl red having a pKa value of +4.8.
• a silver catalyst for the production of ethylene oxide which silver catalyst is prepared by impregnating a carrier using ⁇ -alumina as a principal component thereof and having a sodium content of not more than 0.07% by weight and a specific surface area in the range of l to 5 m2/g with an impregnation having 0.00l to 0.05 gram equivalent, per kg of complete catalyst, of a complex of an alkali metal with boron, a complex of an alkali metal with molybdenum, and/or a complex of an alkali metal with tungsten contained in a decomposable silver solution formulated to give a deposition ratio of 5 to 25% by weight based on the complete catalyst, and then heating and reducing or thermally decomposing the product of impregnation.
• a silver catalyst for the production of ethylene oxide which silver catalyst contains metallic silver particles deposited in a ratio of 5 to 25% by weight based on complete catalyst on an ⁇ -alumina carrier having a sodium content of not more than 0.07% by weight and a specific surface area in the range of 0.5 to 5 m2/g and 0.00l to 0.05 gram equivalent of at least one alkali metal or alkali metal compound per kg of the complete catalyst and in excess of the amount naturally present in the carrier.
• a catalyst for the production of an alkylene oxide which catalyst comprises silver on a porous inorganic refractory carrier containing at least 0.003 gram equiva­lent, per kg of complete catalyst, of caesium and/or rubidium chemically absorbed on the surface of the carrier and a catalyst wherein the amount of the chemically absorbed caesium and/or rubidium falls in the range of 400 to 3,000 ppm based on the complete catalyst per unit surface area, m2/g, of the carrier.
• a catalyst which comprises a granular carrier made of alumina, silica, silica-alumina, or a combination thereof, possessing a surface area approximately in the range of 0.05 to l.5 m2/g, and having a characteristic ability to absorb selectively an alkali metal from a solution of the alkali metal, 5 to 20% by weight, based on complete catalyst, of a silver dispersion deposited on the granular carrier from a solution of an organic silver salt and activated in the presence of molecular oxygen at a maximum temperature not exceeding 500°C for a time long enough to produce an active fresh catalyst and consequently allowed to exist in the form of particles of an average particle diameter approximately in the range of 0.2 to l.0 micron, and at least one alkali metal selected from among caesium, potassium, and rubidium deposited in an amount approximately in the range of l0 to l,000 ppm by weight based on the complete catalyst on the dispersed active silver
• An object of this invention is to provide a novel silver catalyst for the production of ethylene oxide and a method for the manufacture of the silver catalyst.
• Another object of this invention is to provide a catalyst which is able to acquire heretofore unattainable high selectivity and to retain this quality for a long time by causing a reaction promoter of a fixed amount relative to the surface area of the silver in the catalyst to be dispersed and deposited fast on the monomolecular level on the surface of the silver and a method for the manufacture of the catalyst.
• a silver catalyst having fine silver particles dispersed and deposited fast on the outer surface of a porous inorganic refractory carrier and on the inner wall surface of pores in the carrier for use in the production of ethylene oxide by the catalytic gas-phase oxidation of ethylene with molecular oxygen
• silver catalyst is characterised by containing a compound of at least one metal ion selected from the group consisting of caesium, rubidium, potassium, and thallium (monovalent) as dispersed and deposited fast in an amount in the ranged of l ⁇ l0 ⁇ 6 to 5 ⁇ l0 ⁇ 6 gram equivalent per unit surface area, m2 of the silver on the surface of the silver.
• the silver is deposited in an amount in the range of 5 to 25% by weight based on the catalyst, and preferably the silver particles have an average diameter of not more than 2,000 Angstroms.
• the porous inorganic carrier has an apparent porosity in the range of 40 to 70% and a BET specific surface area in the range of 0.l to l0m2/g.
• a preferred material for the carrier is ⁇ - alumina.
• the metal compound may be selected from the group consisting of nitrates, sulphates, carbonates, oxalates, hydroxides, oxides, and acetates.
• the metal ion is deposited in an amount in the range of l.5 ⁇ l0 ⁇ 6 to 4 ⁇ l0 ⁇ 6 gram equivalent per unit surface area, m2, of the silver.
• the silver is deposited in an amount in the range of 5 to 20% by weight based on the catalyst.
• the metal ion is most preferably a caesium ion.
• a method for the manufacture of a silver catalyst having fine silver particles dispersed and deposited fast on the outer surface of a porous inorganic refractory carrier and on the inner wall surface of pores in the carrier for use in the production of ethylene oxide by the catalytic gas-phase oxidation of ethylene with molecular oxygen, which method comprises impregnating the porous inorganic refractory carrier with a solution of a silver compound containing a reducing compound, thermally reducing the product of the impregnation thereby causing fine silver particles to be dispersed and deposited fast on the outer surface of the porous inorganic refractory carrier and on the inner wall surface of the pores in the carrier, removing residual organic material from the resulting composite, and then causing a compound containing at least one metal ion selected from the group consisting of caesium, rubidium, potassium, and thallium (monovalent) to be dispersed and deposited fast in an amount in the range of
• the residual organic material is removed by washing the resulting composite with water or a lower alcohol and then drying the wet composite.
• the drying step subsequent to the step of washing is carried out at temperatures in the range of 50° to l50°C.
• the residual organic material is removed by heating the resulting composite in a current of a gas at a temperature exceeding 200°C thereby decomposing and expelling the residual organic substance.
• the decomposition and expulsion of the residual organic substance are carried out in a current of an inert gas.
• the decomposition and expulsion of the residual organic substance are carried out at a temperature in the range of 200° to 300°C.
• the impregnation and expulsion of the solvent by drying are carried out at temperatures in the range of 0° to 40°C.
• the solvent constituting the solution containing the metal ion compound is a lower alcohol having not more than 3 carbon atoms or a mixed solvent thereof.
• the solution of silver containing a reducing compound is selected from the group consisting of solutions have the silver compound dissolved in alkanolamine or another amine and containing an alkanolamine as a reducing compound, an aqueous silver nitrate soluction containing formalin as a reducing compound, and solutions having silver nitrate dissolved in monoethylene glycol containing a lower acid amide as a reducing compound.
• the caesium compound for example, must be dispersed and deposited in an optimum amount on the monomolecular level on the surface of silver.
• use of the action of adsorption is advantageous.
• the relation between the amount of the monovalent ion such as Cs+ ion adsorbed and the equilibrium concentration of the solution can be regulated by Langmuir Formula of Adsorption, indicat­ing that the adsorption is a monomolecular layer adsorption and possesses the nature of chemical adsorption.
• the amount of saturated adsorption found by the test equals the amount required for covering the surface of silver substantially completely. This fact indicates that the adsorption sites involved in this case are not limited to any special sites on the surface of silver.
• a silver catalyst containing a caesium compound for example, dispersed and deposited fast on the monomolecular level on the surface of silver.
• the amount of caesium ion or other similar monovalent ion to be dispersed and deposited on the silver should be limited to a level falling in the range of l ⁇ l0 ⁇ 6 to 5 ⁇ l0 ⁇ 6 gram equiva­lent, preferably l.5 ⁇ l0 ⁇ 6 to 4 ⁇ l0 ⁇ 6 gram equivalent, per the unit area, m2, of the surface of silver.
• the concentra­tion of the impregnant which is required in fixing the amount of deposition of the caesium compound, for example, within the range can be easily found from the linear formula derivable from the Langmuir's adsorption isotherm to be obtained with respect to the adsorption on the surface of silver. If the caesium compound is dispersed and deposited in any amount exceeding the aforementioned range on the surface of silver, the produced catalyst possesses notably low activity. If this amount falls short of the lower limit of the range, then the produced catalyst possesses notably inferior selectivity.
• the monovalent metal compound such as caesium compound is deposited also on the exposed surface of the carrier.
• the aforementioned range has absolutely nothing to do with the amount of the caesium compound to be deposited on the exposed surface of the carrier. This range is applied exclusively to the amount of the monovalent metal compound such as caesium compound, for example, which is deposited on the surface of silver.
• the amount of the monovalent metal compound which has been dispersed and deposited on the monomolecular level on the surface of silver by virtue of adsorption is determined as follows.
• the amount, A (gram equivalent), of the monovalent metal compound such as the caesium compound adsorbed on the entire surface of silver is calculated as follows.
• A ⁇ (Concentration of prepared impregnant)-(Equilibrium concentration of impregnant for adsorption) ⁇ (Amount of impregnant) ...(l)
• the amount, A includes the amount of the impregnant adsorbed on the exposed surface of the carrier besides the amount of the impregnant adsorbed on the surface of silver.
• the carrier from the same lot in the same amount as used in the preparation of the catalyst is subjected to the same procedure as used in the preparation of the catalyst, excepting the deposition of silver is omitted.
• the carrier is then immersed in a solution containing the caesium ion, for example, in a varying concentration, to obtain data on the relation between the equilibrium concentration for adsorption and the amount of adsorption.
• the data so obtained can be regulated by Langmuir's adsorption formula.
• the amount of adsorption on the surface of the carrier obtained in the same equilibrium concentration for adsorption as the equilibrium concentration for adsorption with the catalyst is calculated similarly to the formula (l). The amount thus calculated is reported as B (gram equivalent).
• the adsorption on the surface of silver is a monomolecular layer adsorption.
• the amount of saturated adsorption to be found from Langmuir type formula substantially agrees with the amount to be found geometrically from the ion radius of caesium or other similar monovalent metal. This fact proves that the adsorption under discussion is an adsorption on the molecular level.
• the inventors wish to emphasise strongly the fact that then the caesium compound is dispersed and deposited in a suitable amount on the surface of silver in accordance with the present invention, there can be realised a plus effect of more than l0% in terms of selectivity for ethylene oxide.
• caesium compound for example, dispersed and deposited refers to the caesium compound deposited on the monomolecular level (with the caesium ions distributed independently one by one).
• the solute which has settled inside the pores is not dispersed or deposited but allowed to remain in the form of clusters of certain size.
• the proportion accounted for by the amount of the monovalent metal compound entrapped increases possibly to the extent of impairing the perform­ance of the catalyst.
• Another method conceivable for lowering the effect of the monovalent metal compound clusters entrapped in the pores comprises immersing the catalyst as a finished product in a solvent thereby allowing the entrapped clusters of monovalent metal compound to be preferentially dissolved out. This method, however, cannot be called desirable because it is not easy to determine and control the adsorbed amount of monovalent metal compound.
• the silver deposited on the carrier is desired to be in a highly dispersed state.
• the effect of the active sites on the surface of the carrier can be decreased and the possible dilution of the effect of this invention can be avoided.
• the catalyst contemplated by the present invention is prepared as follows.
• any of all the known solutions answering the description can be adopted.
• those which permit high dispersion of silver advantageously are solutions containing alkanolamine as a reducing compound and having various silver compounds dissolved in alkanolamine or other amine, an aqueous silver nitrate solution containing formaline as a reducing component, and monoethylene glycol solutions of silver nitrate containing lower acid amides as reducing components.
• alkanolamine or other amine to be used as the reducing compound there can be cited mono-, di-, and triethanolamines, mono-, di-, and tri-n-­propanolamines, mono-, di- and tri-isopropanolamines, n-butanolamines, and isobutanolamines.
• the lower acid amide there can be cited foramide, acetamide, propionic acid amide, glycolic acid amide, and dimethylformamide.
• any of the inorganic silver salts and organic silver salts which are capable of reacting the alkanolamine and consequently forming a complex salt can be adopted.
• Typical examples of the silver salt include silver nitrate, silver carbonate, silver sulphate, silver acetate, silver oxalate, silver lactate, silver succinate, and silver glycolate.
• a lower aliphatic compound of 2 to 6 carbon atoms containing l to 3 alcoholic hydroxyl groups in the molecular unit thereof is advantageously used particularly when a lower acid amine is used as a reducing compound.
• the lower aliphatic compound include monoethylene glycol, diethylene glycol, triethylene glycols, trimethylene glycol, monopropylene glycol, methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, and glycerol.
• the solution of a silver compound selected from among those described above is used to impregnate a porous inorganic carrier.
• porous inorganic carrier any of the porous inorganic carriers hereto­fore known to the art can be adopted.
• a carrier made of alumina and/or silica proves particularly desirable.
• a carrier made of ⁇ -alumina gives favorable results.
• This carrier is desired to have an apparent porosity in the range of 40 to 70%, preferably 50 to 65%, and a BET specific surface area in the range of 0.l to l0 m2/g, preferably 0.2 to 5 m2/g.
• the silver compound containing the reducing compound at a temperature in the range of room temperature to 200°C is reduced to metallic silver and deposited in the form of fine particles on the inner and outer surfaces of the carrier.
• the heating temperature is desired to be kept down to the irreducible minimum. Better results of the heating are obtained when the heating is started at a low temperature and then continued at gradually elevated temperatures.
• the resulting composite is washed with water and/or a lower alcohol preferably in a boiling condition.
• the lower alcohol are aliphatic alcohols of l to 3 carbon atoms, such as methanol, ethanol, isopropanol, and n-propanol.
• This washing treatment is effective in removing alkanolamine and other organic substances from the catalyst and, at the same time, cleaning the surface of the produced active silver and enhancing the activity of the silver.
• the amount of silver to be deposited is desired to fall in the range of 2 to 25% by weight, preferably 5 to 20% by weight, based on the complete catalyst.
• the washed composite is then dried by being heated to a temperature in the range of 50° to l50°C.
• the catalyst obtained consequently has deposited on the carrier fine and uniform silver particles having an average diameter not exceeding l,000 Angstroms.
• the remained organic compound may be removed by heating this composite in a current of a gas at a temperature exceeding 200°C, desirably falling in the range of 200° to 300°C to activate the catalyst.
• the heating effected in an atmosphere containing oxygen at a high temperature exceeding 300°C is undesirable because it entails heavy sintering of silver particles.
• the amount of silver to be deposited is desired to fall in the range of 2 to 25% by weight, preferably 5 to 20% by weight, based on the complete catalyst.
• the catalyst consequently produced is immersed in a solution of a compound of at least one metal selected from the group consisting of caesium, rubidium, potassium, and thallium (monovalent) in a lower alcohol such as methanol or ethanol, for example, so that the compound of at least one metal selected from the group consisting of caesium rubidium, potassium, and thallium (monovalent) wiil be dispersed and deposited fast in an amount in the range of l ⁇ l0 ⁇ 6 to 5 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2 of the silver on the surface of silver.
• a compound of at least one metal selected from the group consisting of caesium, rubidium, potassium, and thallium (monovalent) in a lower alcohol such as methanol or ethanol, for example, so that the compound of at least one metal selected from the group consisting of caesium rubidium, potassium, and thallium (monovalent) wiil be dispersed
• the immersion is made at a temperature of less than 50°C, desirably in the range of 0° to 40°C, and more desirably 0° to 25°C.
• the expulsion of the solvent by drying after the deposition by adsorption is carried out at a temperature of less than 50°C, desirably in the range of 0° to 40°C, and more desirably 0° to 25°C. This expulsion of the solvent is desirably carried out in a current of a gas.
• the compounds of caesium, rubidium, potassium, and thallium are used in the form of nitrates, sulphates, carbonates oxalates, hydroxides, oxides, and acetates.
• Examples of the lower alcohol to be used as a solvent include methanol, ethanol, isopropanol, n-propanol, and mixtures thereof.
• the reaction temperature in the range of l50° to 300°C, preferably l80° to 280°C, the reaction pressure in the range of 2 to 40 kg/cm2G, preferab­ly l0 to 30 kg/cm2G, and the space velocity in the range of l,000 to 30,000 hr ⁇ 1 (STP), preferably 3,000 to 8,000 hr ⁇ 1 is desirably composed of 0.5 to 30% by volume of ethylene, 5 to 30% by volume of carbon dioxide gas, and the balance to make up l00% by volume of an inert gas such as nitrogen, argon, or steam, and a low hydrocarbon such as methane or ethane preferably plus 0.l to l0 ppm (volume) of a halide such as ethylene dichloride, diphenyl chloride, vinyl chloride, monochlorobenzene or dichlorobenzene which is intended as a reaction inhibitor.
• a halide such as ethylene dichloride, diphenyl chloride
• Examples of the source of molecular oxygen to be used in the present invention there can be cited air, oxygen, and oxygen enriched air.
• the chemical action of dispersion and deposition of the caesium ion on the surface of silver is believed to produce a notable steric hindrance effect upon various adsorbates on the surface of silver during the oxidation of ethylene.
• One phase of this effect is manifested on adsorbates of oxygen species by effectively coating adjacent silver atoms and thereby curbing dissociative adsorption of oxygen and suppressing complete oxidation.
• Another phase of the effect is manifested in curbing readsorption of the produced ethylene oxide on silver and suppressing the isomerization of ethylene oxide into acetaldehyde. In both the phases, the effect is believed to contribute directly to enhancing the selectivity for ethylene oxide.
• a silver impregnant was prepared by dissolving 470 g of silver nitrate in 300 g of water, keeping the solution cooled in a water bath, adding 360 g of ethanolamine to the solution, and thoroughly stirring the resulting mixture.
• this impregnant was immersed 2.2 liters of ⁇ -alumina carrier having an apparent porosity of 57% and a BET specific surface area of 0.78 m2/g.
• the impregnation mixture was gradually heated to 90°C, stirred at this temperature for 3 hours, heated further to l20°C, and stirred for 2 hours so as to have the reduced silver dispersed and deposited on the carrier.
• the silver-deposited catalyst thus obtained was washed five times with 3 litres of boiling water and then dried by heating in a current of nitrogen at ll0° to l20°C for 4 hours.
• the dried catalyst was kept immersed in a solution of l.60 g of caesium carbonate in l,6l5 ml of reagent grade ethanol at 20°C for 3 hours. Subsequently, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining in the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst obtained at this point was found to have l3.5% by weight of silver deposited thereon.
• the surface area of this silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the surface of silver was 2.3 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• An externally heating type double-pipe stainless steel reactor 25 mm in inside diameter and 6,000 mm in length was packed with the catalyst.
• a mixed feed gas consisting of 20% by volume of ethylene, 8% by volume of oxygen, 7% by volume of carbon dioxide gas, and the balance to make up l00% by volume of methane, nitrogen, argon, and ethane and further containing 2 ppm of ethylene dichloride was introduced into the catalyst bed and left reacting under a reaction pressure of l5 kg/cm2 G at a space velocity of 6,500 hr ⁇ 1.
• the results obtained after 30 days reaction are shown in Table l. Even after 6 months' continued reaction, this catalyst retained the performance intact.
• a catalyst was prepared following the procedure of Example l, except that a solution of l.25 g of rubidium carbonate in l,6l5 ml of reagent grade methanol was used in place of the solution of l.60 g of caesium carbonate in l,6l5 ml of reagent grade ethanol.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of rubidium ion deposited by adsorption on the silver was 2.6 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l, except that a solution of l.30 g of potassium nitrate in l,6l5 ml of reagent grade methanol was used in the place of the solution of l.60 g of caesium carbonate in l,6l5 ml of reagent grade ethanol.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.03 m2/g
• the exposed surface area of the carrier was 0.l4 m2/g
• the amount of potassium ion deposited by adsorption on the silver was 2.8 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of thallium (monovalent) ion deposited by adsorption on the silver was 2.7 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l, except that an ⁇ -alumina carrier having an apparent porosity of 54% and a BET specific surface area of l.l2 m2/g was used instead and a solution of 2.40 g of caesium carbonate in l,600 ml of reagent grade ehtanol was used in place of the solution of l.60 g of caesium carbonate in l,6l5 ml of reagent grade ethanol.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.25 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 2.9 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver-containing impregnant was prepared by dissolving 520 g of silver nitrate in 300 g of water, keeping this solution cooled in a water bath, adding 400 g of ethanolamine to the cooled solution, and thoroughly stirring the resulting mixture.
• this impregnant was immersed 2.2 litres of ⁇ -alumina carrier having an apparent porosity of 60% and a BET specific surface area of 2.80 m2/g.
• the impregnation mixture was gradually heated to 90°C, stirred at this temperature for 3 hours, further heated to l20°C, and stirred for 2 hours to have the reduced silver dispersed and deposited on the carrier.
• the silver-­deposited catalyst conseuquently obtained was washed five times with 3 litres of boiling water and was then dried by heating in a current of nitrogen at ll0° to l20°C for 4 hours.
• the dried catalyst was kept immersed in a solution of 4.65 g of caesium carbonate in l,650 ml of reagent grade ethanol at 20°C for 3 hours. Subsequently, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a flow rate of 50 litres/minute for 5 hours thorough evaporation and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst thus obtained was found to have l4.7% by weight of silver deposited thereon.
• the surface area of the silver was 2.42 m2/g of catalyst
• the exposed surface area of the carrier was l.l8 m2/g of catalyst
• the amount of caesium ion deposited by adsorption on the silver was 2.l ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example 6, excepting 320 g of water was used in place of 300 g of water, an ⁇ -alumina carrier having an apparent porosity of 62% and a BET specific surface area of 3.53 m2/g was used instead, and a solution of 5.l0 g of caesium carbonate in l,680 ml of reagent grade ethanol was used in place of the solution of 4.65 g of caesium carbonate in l,650 ml of reagent grade ethanol. The catalyst thus obtained was found to have l4.8% by weight of silver deposited thereon.
• the surface area of the silver was 2.86 m2/g of catalyst, the exposed surface area of the carrier was l.58 m2/g of catalyst, and the amount of caesium ion deposited by adsorp­tion on the silver was 2.0 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver impregnant was prepared by dissolving 470 g of silver nitrate in 300 g of water, keeping the solution cooled in a water bath, adding 360 g of ethanolamine to the cooled solution, and thoroughly stirring the resulting mixture.
• the impregnant was immersed 2.2 litres of ⁇ -­alumina carrier having an apparent porosity of 57% and a BET specific surface area of 0.78 m2/g.
• This impregnation mixture was gradually heated to 90°C, stirred at this temperature for 3 hours, then heated further to l20°C, and stirred for 2 hours so as to have the reduced silver dispersed and deposited on the carrier.
• the silver-­deposited catalyst consequently obtained was washed 5 times with 3 litres of boiling water and then heated in a current of nitrogen at ll0° to l20°C for 4 hours.
• the dried catalyst was kept immersed in a solution of l.60 g of caesium carbonate in l,6l5 ml of reagent grade ethanol of 0°C for 3 hours. Then, the catalyst was deprived of excess impregnant and swept with dry nitrogen flowing at a rate of 50 litres/minute for 8 hours thorough evaporation and expulsion of the solvent remaining in the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 0°C.
• the catalyst consequently obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of this silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 2.4 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver impregnant was prepared by dissolving 470 g of silver nitrate in 700 g of monoethylene glycol, adding l90 g of formaldehyde to the solution, and thoroughly stirring the resulting mixture.
• the impregnant was immersed 2.2 liters of ⁇ -alumina carrier having an apparent porosity of 57% and a BET specific surface area of 0.78 m2/g.
• This impregnation mixture was stirred and, at the same time, heated to l30°C, stirred at this temperature for 2 hours, further heated to l60°C, and stirred for 2 hours so as to have the reduced silver dispersed and deposited on the carrier.
• the silver-deposited catalyst consequently obtained was washed 8 times with boiling water and then dried by heating in a current of nitrogen at ll0° to l20°C for 4 hours.
• the dried catalyst was kept immersed in a solution of l.45 g of caesium carbonate in l,6l5 ml of reagent grade ethanol at 20°C for 3 hours. Then, the catalyst was deprived of excess impregnant and swept with dry nitrogen flowing at a rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining inside the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst consequently obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of this silver was 0.9l m2/g of catalyst, the exposed surface area of the carrier was 0.22 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 2.3 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver impregnant was prepared by dissolving 470 g of silver nitrate in 300 g of water, keeping the solution cooled in a water bath, adding 360 g of ethanolamine to the cooled water, and thoroughly stirring the resulting mixture.
• the impregnant was immersed 2.2 litres of ⁇ -alumina carrier having an apparent porosity of 57% and a BET specific surface area of 0.78 m2/g.
• This impregnation mixture was gradually heated to 90°C, stirred at this temperature for 3 hours, then heated further to l20°C, and stirred for 2 hours so as to have the reduced silver dispersed and deposited on the carrier.
• the silver-­deposited catalyst consequently obtained was washed 5 times with 3 litres of boiling water and then dried by heating in a current of nitrogen at ll0° to l20°C for 4 hours.
• the dried catalyst was kept immersed in a solution of 5.05 of caesium carbonate in l6l5 ml of reagent grade ethanol at 20° for 3 hours. Subsequently, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a flow rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 5.5 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Control l, except that 0.24 g of caesium carbonate was used in place of 5.05 g of caesium carbonate.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of this silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 0.4 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was obtained by following the procedure of Control l, except that l.45 g of caesium carbonate was used in place of 5.05 g of caesium carbonate, the carrier was kept immersed in the ethanol solution of caesium carbonate at 70°C for 3 hours, and the outer wall temperature of the catalyst bed during the evaporation and expulsion of the solvent retained in the pores of the carrier was kept at 70°C.
• the catalyst thus obtained was found to have l3.5% by weight of silver deposited thereon.
• the surface area of the silver was l.03 m2/g of catalyst, the exposed surface area of the carrier was 0.l4 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 0.8 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver impregnant was prepared by mixing 420 g of silver oxalate with 200 g of water to produce a slurry, keeping the slurry cooled in a water bath, adding 360 g of ethanolamine to the cooled slurry, and thoroughly stirring the resulting mixture.
• the impregnant was immersed 2.2 liters of ⁇ -alumina carrier having an apparent porosity of 55% and a BET specific surface area of 0.70 m2/g.
• the impregnation mixture was stirred and heated to 90°C for l hour, then heated further to l20°C, and stirred for l hour so as to have the reduced silver dispersed and deposited on the carrier.
• the silver-deposited catalyst was heated in a current of air at 260°C for 24 hours.
• this catalyst was kept immersed in a solution of l.l6 g of caesium carbonate in l,580 ml of reagent grade ethanol at 20°C for 3 hours. Subsequently, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst consequently obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of this silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorp­tion on the silver was 2.0 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l0, except that a solution of 0.95 g of rubidium carbonate in l,580 ml of reagent grade methanol was used in place of the solution of l.l6g of caesium carbonate in l580 ml of reagent grade ethanol.
• the catalyst thus obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of rubidium ion deposited by adsorption on the silver was 2.3 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared follwoing the procedure of Example l0, except that a solution of 0.95 g of potassium nitrate in l580 ml of reagent grade methanol was used in place of the solution l.l6 g of caesium carbonate in l580 ml of regent grade ethanol.
• the catalyst thus obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of potassium ion deposited by adsorption on the silver was 2.4 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l0, except that 2.00 g of thallium acetate was used in place of l.l6 g of caesium carbonate.
• the catalyst thus obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of thallium (monovalent) ion deposited by adsorption on the silver was 2.5 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l0, except that an ⁇ -alumina carrier having an apparent porosity of 53% and a BET specific surface area of l.05 m2/g was used instead and a solution of 2.0 g of caesium carbonate in l,560 ml of reagent grade ethanol was used in place of the solution of l.l6 g of caesium carbonate in l,580 ml of reagent grade ethanol.
• the catalyst thus obtained was found to have l3.6% by weight of silver deposited thereon.
• the surface area of the silver was 0.60 m2/g of catalyst, the exposed surface area of the carrier was 0.60 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 2.6 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a catalyst was prepared following the procedure of Example l0, except that the impregnation temperature of the ethanol solution of caesium carbonate and upper limit temperature of the catalyst bed during drying was changed from 20°C to 0°C and flowing time of nitrogen during drying was changed from 5 hours to 8 hours.
• the catalyst thus obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 2.l ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver-deposited catalyst obtained following the procedure of Example l0 was kept immersed in a solution of 4.50 g of caesium carbonate in l,580 ml of reagent grade ethanol at 20°C for 3 hours. Subsequently, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst consequently obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorp­tion on the silver was 6.l ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver-deposited catalyst prepared following the procedure of Example l0 was kept immersed in a solution of 0.22 g of caesium carbonate in l,580 ml of reagent grade ethanol at 20°C for 3 hours. Then, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a rate of 50 litres/minute for 5 hours for thorough evaporation and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was prevented from exceeding 20°C.
• the catalyst consequently obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 0.4 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• a silver catalyst prepared following the procedure of Example l0 was kept immersed in a solution of l.l6 g of caesium carbonate in l,580 ml of reagent grade ethanol at 70 °C for 3 hours. Then, the catalyst was deprived of excess impregnant and further swept with dry nitrogen flowing at a rate of 50 litres/minute for 3 hours for thorough evapora­tion and expulsion of the solvent remaining within the pores of the carrier. In this while, the temperature of the catalyst was kept at 70°C.
• the catalyst consequently obtained was found to have l3.2% by weight of silver deposited thereon.
• the surface area of the silver was 0.50 m2/g of catalyst, the exposed surface area of the carrier was 0.36 m2/g of catalyst, and the amount of caesium ion deposited by adsorption on the silver was 0.8 ⁇ l0 ⁇ 6 gram equivalent per the unit area, m2, of the surface of the silver.
• the conventional method which obtains a catalyst by the addition of a reaction promoter pays absolutely no consideration to the dispersion and deposition of at least one metal ion selected from the group consisting of caesium, rubidium, potassium, and thallium (monovalent) on the surface of silver and, with respect to the range of amount considered effective, only specifies a superificial amount departing far from the substantial truth.
• the catalyst produced by the conventional method fails to acquire satisfactory performance or sufficient catalyst life.
• the catalyst of the present invention realises heretofore unattainable high selectivity and long catalyst life and, therefore, enjoys great economic advantage.

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• 1986
  • 1986-11-05 AU AU64902/86A patent/AU586048B2/en not_active Ceased
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